The present invention relates to a chain belt, which spans between an input pulley and an output pulley, for transmitting torque from the input pulley to the output pulley.
More particularly, the present invention relates to improvements in the chain belt, which includes a plurality of links, a plurality of pins and a plurality of V-shape blocks. The chain belt spans between an input pulley and an output pulley of a continuously variable transmission mounted on a vehicle.
A chain belt is disclosed in Japanese Utility Model publication No. 3919/64. The Japanese publication No. 3919/64 discloses a chain belt which includes a plurality of links, a plurality of pins and a plurality of V-shape blocks. The chain belt spans between an input pulley and an output pulley and each of the input and output pulleys includes a V-shape groove thereon. The plurality of V-shape blocks of the chain belt are located within the V-shape grooves of the input and output pulleys. The V-shape block includes an opening therewithin and the link includes a pair of recesses and a pair of apertures. One aperture is defined within each end portion of the link. The pair of recesses are defined within an intermediate portion of the link in the longitudinal direction of the link (i.e., the pair of recesses are located between the two end portions of the link), and one recess is defined on each of the outer and inner sides of the link. When the link is assembled to the V-shape block, the recesses engage with horizontal beams of the V-shape block which define upper and lower edges of the opening of the V-shape block. One of the plurality of pins is inserted into the aperture of the link and each of the plurality of links is connected to another of the plurality of links by the pin. In assembly condition, a continuous V-shape loop of the chain belt is formed by the plurality of links, the plurality of V-shape blocks and the plurality of pins.
However, as shown in FIG. 31, when this conventional continuous V-shape loop of the chain belt 910 spans between the input and output pulleys 906 and 907, the continuous V-shape loop of the chain belt 910 is bent downwardly between the input and output pulleys 906 and 907 by the weight of the chain belt 910. As a result, when the chain belt 910 rotates with the input and output pulleys 906 and 907, the chain belt 910 oscillates up and down between the input and output pulleys 906 and 907 and the chain belt 910 hits the input and output pulleys 906 and 907. The oscillation of the chain belt 910 makes noise and reduces the durability of the plurality of links 951 of the chain belt 910 and the input and output pulleys 906 and 907.
Further, as shown in FIG. 32, stress concentrates on a corner 958 of the recess 957 of the conventional link 951, so that the conventional link 951 has damage on the corner 958.
Another conventional chain belt is disclosed in Japanese Utility Model Laid open No. 85745/86. The Japanese Utility Model discloses the conventional chain belt which includes a plurality of links, a plurality of pins and a plurality of V-shape blocks. To prevent the chain belt from bending downwardly between the input and output pulleys, each of the plurality of links includes a pair of side projections. When the chain belt spans between the input and output pulleys, one of the side projections of a link is in contact with one of the side projections of an another link which is located adjacent to the first link.
However, the link does not have a wide thickness in the lateral direction of the chain belt, so that when the link does not align with the other link in the longitudinal direction of the chain belt, the side projections of the links cannot be in contact with each other.
As a result, the side projections of the links cannot prevent the chain belt from bending downwardly, and when the chain belt is rotated with the input and output pulleys, the chain belt oscillates up and down between the input and output pulleys. Accordingly, the chain belt makes noise and the durability of the chain belt and the input and output pulleys is reduced.
Further, a conventional chain belt is disclosed in Japanese Patent Laid Open No. 24853/86. The Japanese Patent discloses the conventional chain belt which includes a plurality of first links, a plurality of second links, a plurality of pins and, a plurality of V-shape blocks.
The shape of the first link is different from the shape of the second link. The first link includes a pair of side projections and the second link includes a center lateral projection. When the chain belt spans between the input and output pulleys, the side projection of the first link is in contact with the center lateral projection of the second link, such that a combination of the first and second links prevents the chain belt from bending downwardly between the input and output pulleys.
However, in a manufacturing step, the first and second links must be produced separately and the manufacturing cost of the chain belt increases.
Further, in an assembling step, the first link must be assembled between a pair of the second links and the assembly time and cost of the chain belt increase.